Tisdale, who found fame playing Sharpay in the smash Disney musical franchise, will appear in the sitcom's Valentine's Day episode, according to Entertainment Weekly.
She will play a 'fake' girlfriend and love interest for Lucas Neff's character Jimmy Chance and cause friction between Chance and Sabrina (Shannon Woodward).
Tisdale's recent TV credits include The CW's Hellcats and the voiceover role of Candace Flynn in Phineas and Ferb.
Raising Hope airs on Tuesdays at 9.30/8.30c on Fox. Season two will start in the UK on Sky1 in the New Year.
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